Pentagon asks for major budget increase amid threats from Russia, China and North Korea

Washington (CNN)Citing increasing threats from China and Russia, the Pentagon is asking for a major boost in military spending for 2019, requesting Congress approve a budget of $686 billion -- one of the largest in US history.

"Great power competition, not terrorism, has emerged as the central challenge to US security and prosperity," Under Secretary Of Defense David L. Norquist told reporters Monday following the unveiling of the budget proposal.

"It is increasingly clear that China and Russia want to shape a world consistent with their authoritarian model-gaining veto authority over other nations' economic, diplomatic, and security decisions," the budget document says.

China "seeks Indo-Pacific regional hegemony in the near-term," the document says, but in the long term seeks to "achieve global preeminence" over the US.

The document follows confirmed reports of continued Chinese island building in the South China Sea, with facilities being constructed in the Spratly and Paracel islands and Scarborough Shoal. Just last week the office website of the Chinese People's Liberation Army (PLA) carried an article touting patrols of Su-35 fighter jets over the area.

The patrols of the long-range, twin-engine jets show the "PLA Air Force's resolution to implement missions in the new era and firmly maintain national sovereignty and security and maritime interests," the article quotes Wang Mingzhi, a professor with the Chinese PLA Air Force Command Academy, as saying.

The document says "Russia has violated the borders of nearby nations and pursues veto power over the economic, diplomatic, and security decisions of its neighbors."

Moscow is also trying to "shatter the North Atlantic Treaty Organization," the post-World War II Western alliance that has been the bulwark of security in Western Europe, the budget document states.

Russian military aircraft have been involved in several near collision incidents with US warplanes over the Black Sea and Syria in the past few months as Moscow challenges US influence.

And last summer Vladamir Putin ordered what analysts called an unprecedented display of Russia's military might, with a day of naval parades from Vladivostok in the east to St. Petersburg in the west, with additional shows in by Russian forces in Syria and Crimea.

The budget plan puts an emphasis on missile defense, with additions to systems that have been identified as key to countering the threat posed by North Korea's nuclear missile program.

It calls for the procurement of 37 Standard Block 1B missile for the Navy's Aegis missile defense ships and sites on shore.

In the Pacific, the Aegis system is deployed on more than a dozen guided-missile destroyers and cruisers that in theory could shoot down missiles fired by North Korea.